Citing a desire to improve security, Clorox says it will stop making its namesake bleach out of chlorine and sodium hydroxide.

Instead, the big household-products company will purchase high-strength bleach of up to 15% concentration and dilute it to household strength of 6%. The company will convert its Fairfield, Calif., plant within the next six months and switch its six other U.S. plants over the coming years.

Clorox’ announcement came three days before the House of Representatives was set to take up plant security legislation (H.R. 2868) that would require high-risk chemical plants and water-treatment facilities to use safer processes or chemicals.

The environmental group Greenpeace is lauding Clorox for eliminating risk from the use and transport of chlorine. “By ending the use of chlorine gas, Clorox also proves that eliminating these risks is both technically feasible and a smart business decision,” says Rick Hind, Greenpeace’s legislative director.

Greenpeace says it sent a letter to Clorox CEO Don Knauss in February seeking a meeting on the risks related to chlorine gas. The group says it learned of the conversion plan in May during a meeting with Knauss. Greenpeace is now calling on large chemical firms to switch away from chlorine to safer raw materials.

Clorox isn’t disclosing the cost of the transition or the companies from which it will buy high-strength bleach. It does say, however, that it expects no chlorine movement in its U.S. supply chain, including to its bleach suppliers. That precludes companies that make bleach out of shipped-in chlorine and sodium hydroxide—the bulk of the industry.

Timothy Maegly, vice president of high-strength bleach maker BleachTech, points out that two other classes of bleach supplier can meet the no-movement condition: chlorine producers such as Olin that make bleach on-site and companies such as BleachTech that make bleach directly from salt without isolating chlorine.

Clorox’ conversion won’t cause a big spike in demand for high-strength bleach, Maegly predicts, but it’s indicative of the pressures on traditional bleach companies to comply with U.S. plant-security requirements. “Homeland Security is already knocking on their door,” he says.